Hi All,

We upgraded a Vplex metro config to GeoSynchrony 5.1P3 (5.1.0.03.00.07).  Since then the enviroment ran stable.

However last weeks issue arised after a ESX-reboot (due to HBA-replacement): Windows MSCS-cluster-VM’s, which did not want to start again after the ESX-host reboot..

My suspection at this moment is that the VPLEX-upgrade to 5.1P3 has led to a change in behavior towards MSCS cluster VMs, which causes the dead paths.

 

What happened?

During normal operations the second node of the Windows2003-MSCS clusters (B-nodes) ware being shut down.

1. Maintenance on the server was performed (defective HBA replaced and zoning adapted to those changes), and the ESX-server was rebooted
2. All VMFS’s come up normally, but MSCS cluster nodes cannot start. Cause is that RDM-luns’s have all paths dead.
3. A reboot/rescan of the ESX-host does not help
4. A check of zoning, VPlex configuration etc does notindicate any issues at those layers. (EMC support involved, no Plex-config-issues or errors found)

The current state is that in the MSCS clusters still only 1 node is active on the primary location (A-nodes), and the second node still unable to start due to dead paths.

Further investigation proved that the issue only occurs with RDM-luns used by Windows2003 clusters. The issue does not occur on RDM-luns used by Windows2008 clusters and on RDM-luns not used for MSCS.

The difference what I see at VPLEX-level is that the RDM-luns used for Win2003 have SCSI-2 locks active, and the RDM’s in use by Win2008 clusters have SCSI-3 locks.

My feeling now is that VPLEX behavior for SCSI-2 reservations has been changed towards 5.1SP3 in a way that when a SCSI-2 lock is active on a lun the metadata of those luns cannot be read either by other hosts, causing the dead paths at ESX-level.

Does anybody have any suggestion or idea if there is a parameter/option at VPLEX level which controls how SCSI-2 reservations are being enforced at VPLEX-level, and if we can change a parameter there to get this issue resolved?

Thanks in advance for your thoughts on this.

Vplex-config:

SiteA: Vplex-engine (2dirs), VNX5500, ESX5.0 host with MSCS-nodes-A.

SiteB: Vplex-engine (2dirs), VNX5500, ESX5.0 host with MSCS-nodes-B.

Each site dedicated FC-SAN. VPLEX interconnect 10GbE IP.